How To Fix M8644 - Field & is not defined as a search field in this line layout

SAP Error Message - Details

• Message type: E = Error

• Message class: M8 - Invoice Verification/Valuation

• Message number: 644

• Message text: Field & is not defined as a search field in this line layout

What causes this issue?

The cursor is on a field which is not a search field in the current
line structure.

How to fix this error?

If you position the cursor on the command line and select F5, a window
appears which contains the fields which you can search for in the
current line structure.
You can only search for the content of other fields in the following
way:
select a line structure in which the field is defined as a search field.
your system administrator can define the field as a search field in the
current line structure in invoice verification via customizing.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message M8644 - Field & is not defined as a search field in this line layout ?

  The SAP error message M8644, which states "Field & is not defined as a search field in this line layout," typically occurs in the context of SAP's Material Management (MM) module, particularly when working with line layouts in transaction codes like ME21N (Create Purchase Order) or ME22N (Change Purchase Order).
  Cause:
  This error arises when you attempt to use a field in a search or filter operation that has not been defined as a search field in the current line layout configuration. This can happen due to:
  
  Customizations: If the line layout has been customized and the field in question was not included in the layout.
  Field Configuration: The field may not be set up correctly in the system to be used as a search field.
  User Authorizations: The user may not have the necessary authorizations to access certain fields.
  
  Solution:
  To resolve the M8644 error, you can take the following steps:
  
  
  Check Line Layout Configuration:
  
  Go to the transaction code where the error occurs (e.g., ME21N).
  Navigate to the layout settings (usually found under the "Settings" menu).
  Verify if the field in question is included in the line layout. If not, you may need to add it.
  
  
  
  Modify the Layout:
  
  If you have the necessary permissions, you can modify the line layout to include the missing field.
  Use the "Change Layout" option to add the field to the layout.
  
  
  
  Consult with SAP Basis or Functional Team:
  
  If you do not have the necessary permissions to change the layout, contact your SAP Basis or functional team to assist with the configuration.
  
  
  
  Check User Authorizations:
  
  Ensure that the user has the appropriate authorizations to access the field. This may involve checking roles and authorizations assigned to the user.
  
  
  
  Review Documentation:
  
  Check SAP documentation or notes related to the specific transaction and field to ensure there are no known issues or additional configurations required.
  
  
  
  Related Information:
  
  Transaction Codes: ME21N, ME22N, ME23N (for Purchase Orders).
  Line Layouts: These are configurations that determine which fields are displayed and how they can be used in transactions.
  SAP Notes: Search for relevant SAP Notes in the SAP Support Portal that may address specific issues related to line layouts and error messages.
  
  If the issue persists after following these steps, consider reaching out to SAP support for further assistance.